Method for estimating a blood sugar condition

ABSTRACT

A blood sugar condition is estimated by measuring a urine sugar value, discriminating whether it is less than a discriminating method classification boundary value, when it is less, obtaining an averaged value of measured urine sugar values during a past predetermined period of time, measured at the same time of day as the latest measurement, calculating the difference between the averaged and measured urine sugar values, when the difference is not less than a positive discriminating reference difference, discriminating as being a blood sugar value decrease, when the measured value is not less than the discriminating method classification boundary value, obtaining an averaged value of all measured values during the past predetermined period of time, calculating a ratio between the measured and averaged values, and, when the ratio is not greater than a first discriminating reference ratio, discriminating as being the blood sugar value decrease.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a division of co-pending application Ser. No.12/058,778 filed on Mar. 31, 2008, which claims foreign priority toJapanese Application Nos. 2007-093129 and 2008-029717 filed on Mar. 30,2007 and Feb. 8, 2008, respectively. The entire content of each of theseapplications is hereby expressly incorporated by reference.

FIELD OF INVENTION

This invention relates to a blood sugar condition estimation method andapparatus for estimating a blood sugar condition from a urine sugarmeasurement. In particular, this invention relates to a urine sugarcondition estimation method for estimating a urine sugar conditionviewed at a comparatively long span, not an instantaneous value of urinesugar value.

BACKGROUND OF INVENTION

The most important matter in medical treatment for diabetes is a bloodsugar control. HbA1c (hemoglobin A1c, which is also calledGlycohemoglobin) is one of indications of a blood sugar condition. HbA1cis the hemoglobin nonenzymatically combined with sugar. HbA1c is notinfluenced by a temporary change of blood sugar caused by meal andothers. However, if a high blood sugar condition continues, theproportion of the combination rises, with the result that HbA1c becomeshigh. Thus, HbA1c is used as an indication of the blood sugar conditionin one to two months prior to measurement, because the life of thehemoglobin is on the degree of 120 days.

Generally, a diabetic outpatient is subjected to a measurement of HbA1cin a visit to clinic of once a month, and whether the blood sugarcondition is good or bad is evaluated in comparison with precedingmeasured values such as a measured value obtained in the latest month,etc. Based on the result of the evaluation, a policy of pharmacotherapyis discriminated, and/or a guidance for meal and exercise therapy isshown, in order to approach a normal value. Therefore, the diabetic hasa very high interest in the change of HbA1c.

As a HbA1c measuring method, it is a general practice to sample blood inan medical institution and to perform a LA method (latex aggregationmethod) or a HPLC method (high-performance liquid chromatography method)by use of a clinical laboratory test apparatus. Incidentally, HbA1c maybe measured in a medical examination, not only as an indication of theblood sugar condition but also for screening diabetes

In the meanwhile, it is also possible to directly measure a blood sugarvalue in order to confirm the blood sugar condition. It is general thatafter blood is sampled in the medical institution, the blood sugar valueof the sampled blood is measured by the clinical laboratory testapparatus. On the other hand, by use of a simplified blood sugarmeasuring device, it is possible to measure in home with no assistanceof a medical professional, and an insulin using person daily utilizesthe simplified blood sugar measuring device.

As mentioned above, HbA1c is a very important item as the indication ofthe blood sugar condition, and is very highly interesting to medicalprofessionals and patients. However, the measurement of HbA1c has to becarried out in the medical institution. On the other hand, since HbA1cis subjected to a strong influence of a daily blood sugar value, itmight be possible to estimate HbA1c on the basis of a daily blood sugarmeasurement. However, an “in-day” change of the daily blood sugar valueis very large because of influence of meal, and therefore, a frequentmeasurement is required. The simplified blood sugar measuring devicemight be utilized to measure the daily blood sugar value, but is notconvenient to the frequent measurement, because of invasion by centesisand because of a measurement cost. Therefore, it does not become ameasuring method for the HbA1c estimation.

As mentioned above, a diabetic is usually blood-sampled in the medicalinstitution monthly or bi-monthly so that the blood sugar level, HbA1cand others are measured and, if necessary, the diabetic receives a lifeguidance. However, it is the most desirable to the diabetic if thediabetic can know a daily blood sugar condition so that the diabetic cancontrol the meal in accordance with the known blood sugar condition.

In the meanwhile, in comparison with the blood sugar measurement, aurine sugar measurement can be relatively easily carried out because ofits non-invasiveness. In addition, it is reported that since the urinesugar measurement dynamically reflects the change of the blood sugarvalue exceeding a sugar elimination renal threshold, it is possible toconfirm and control a high level of postcibal blood sugar on the basisof the urine sugar measurement (Non-Patent Document 1). In aconventional urine sugar measurement, a qualitative analysis using aurine sugar inspection test paper was dominant. However, the Non-PatentDocument 1 is reporting that as a biochemistry measuring instrument, aurine sugar measuring device has been used which makes a quantitativemeasurement possible in home. The urine sugar meter as the biochemistrymeasuring instrument is disclosed in for example Patent Document 1 andPatent Document 2.

-   Non-Patent Document 1: Journal of the Takasaki Medical Association,    Vol. 55, Separate Volume, pp 75-79-   Patent Document 1: JP-09-297120-A-   Patent Document 2: JP-2006-153849-A-   Non-Patent Document 2: “DIABETES”, Vol. 42, No. 11, 1999, pp 957-961-   Non-Patent Document 3: “Diabetes Care”, Vol. 25, No. 2, 2002, pp    275-278-   Non-Patent Document 4: “Diabetes Care”, Vol. 27, No. 2, 2004, pp    335-339

On the other hand, a correlation among the blood sugar value, HbA1c andthe urine sugar value has been already researched (Non-Patent Document2, Non-Patent Document 3 and Non-Patent Document 4). It is consideredthat if the blood sugar value rises up or falls down to becomehyperglycemia in which the blood sugar value exceeds the sugarelimination renal threshold (which is generally considered to be 160 to180 mg/dL although there is an individual difference), the urine sugarvalue will rise up or fall down as a matter of course. That is to say,if a risen or fallen urine sugar value continues for a considerablenumber of days, the blood sugar value should greatly rise up or falldown, with the result that HbA1c should correspondingly rise up or falldown after the considerable number of days. However, it is not possibleto predicate how many days the risen or fallen urine sugar value isrequired to continue until any change appears in HbA1c, and what degreeof magnitude is the actual change of HbA1c, because of a largeindividual difference between humans being. Similarly, because of thelarge individual difference, it is not possible to accurately convert aspecific value α of the urine sugar value into a specific value β of theblood sugar value. In the prior art, accordingly, there is no method forknowing the blood sugar value from the urine sugar value.

From a different viewpoint, even if it can be said that if a risen orfallen urine sugar value continues for a considerable number of days,the HbA1c will certainly rise up or fall down, if a warning that “theblood sugar value rose” is given after the HbA1c has actually risen, itmeans that the diabetic has been resultantly left in a risen blood sugarcondition for the considerable number of days, and the value of thewarning is not so high. Rather than to know an accurate value of HbA1cjust after the measurement of the urine sugar value, it is moreimportant to diabetics to know whether the HbA1c is in an improvingtendency or in a deteriorating tendency.

In addition, focusing to the urine sugar value per se, the measuredvalue of the urine sugar value is an instantaneous value and has a largeindividual difference, and considering a specific individual, the urinesugar value greatly depends upon a condition of the same individual whenthe measurement was carried out. Therefore, although it is possible toknow the instantaneous value of the urine sugar value, it is notpossible to predicate whether the urine sugar value is in an improvingtendency or in a deteriorating tendency, unless the instantaneous valuetakes an extreme value.

SUMMARY OF INVENTION

By studying how a significant correlation between the blood sugar valueand the urine sugar value just after the measurement of the urine sugarvalue is obtained, the inventor of this invention came to thisinvention.

Accordingly, an object of this invention is to evaluate and estimate ablood sugar condition from the result of a non-invasive urine sugarmeasurement. In particular, it is to provide a blood sugar conditionestimation method and apparatus capable of indicating an improvement ora deterioration of HbA1c from a stored measurement result of the urinesugar value, by focusing to HbA1c which is one indication of the bloodsugar condition and by studying the correlation between HbA1c and theurine sugar value.

In addition, another object of this invention is to evaluate a bloodsugar condition or to estimate whether HbA1c is in an improving tendencyor in a deteriorating tendency, from a latest urine sugar value or urinesugar values during a predetermined period including the latest urinesugar value, or alternatively to set a urine sugar value as a lifestyleimprovement target and to discriminate whether or not the goal isachieved.

Still another object of this invention is to provide a urine sugarcondition estimation for estimating, as an indication of a healthcondition, whether the urine sugar condition is in an improving tendencyor alternatively in a deteriorating tendency, from a latest urine sugarvalue or urine sugar values during a predetermined period including thelatest urine sugar value.

According to this invention, there is provided a urine sugar conditionestimation method, comprising the steps of:

(1) measuring a urine sugar value A;

(2) obtaining an averaged value X of measured urine sugar valuesmeasured during a past predetermined period of time, always includingall measured urine sugar values measured at the same timing in a one-daylife as the timing when said latest measured urine sugar value A wasmeasured;(3) discriminating whether or not said measured urine sugar value A isless than a discriminating method classification boundary value;(4) when the measured urine sugar value A is less than thediscriminating method classification boundary value, calculating adifference between said averaged value X and said measured urine sugarvalue A;(5) when said difference {X−A} is not less than a positivediscriminating reference difference, discriminating as being a urinesugar value decrease;(6) when the measured urine sugar value A is not less than thediscriminating method classification boundary value, calculating a ratiobetween said measured urine sugar value A and said averaged value X;and,(7) when said ratio {A/X} is not greater than a first discriminatingreference ratio, discriminating as being the urine sugar value decrease.

More particularly, the urine sugar condition estimation method inaccordance with this invention, further comprises the steps of:

(8) when said difference {X−A} is not greater than a negativediscriminating reference difference, discriminating as being a urinesugar value increase;

(9) when said difference {X−A} is greater than said negativediscriminating reference difference but less than said positivediscriminating reference difference, discriminating as being no changein the urine sugar value;

(10) when said ratio {A/X} is not less than a second discriminatingreference ratio, discriminating as being the urine sugar value increase;and

(11) when said ratio {A/X} is greater than said first discriminatingreference ratio but less than said second discriminating referenceratio, discriminating as being no change in the urine sugar value.

In addition, according to this invention, there is provided a bloodsugar state estimation method, comprising the steps of:

(1) measuring a urine sugar value A;

(2) obtaining an averaged value X of measured urine sugar valuesmeasured during a past predetermined period of time, always includingall measured urine sugar values measured at the same timing in a one-daylife as the timing when said latest measured urine sugar value A wasmeasured;(3) discriminating whether or not said measured urine sugar value A isless than a discriminating method classification boundary value;(4) when the measured urine sugar value A is less than thediscriminating method classification boundary value, calculating adifference between said averaged value X and said measured urine sugarvalue A;(5) when said difference {X−A} is not less than a positivediscriminating reference difference, discriminating as being a bloodsugar value decrease;(6) when the measured urine sugar value A is not less than thediscriminating method classification boundary value, calculating a ratiobetween said measured urine sugar value A and said averaged value X;and,(7) when said ratio {A/X} is not greater than a first discriminatingreference ratio, discriminating as being the blood sugar value decrease.

More particularly, the blood sugar state estimation method in accordancewith this invention, further comprises the steps of:

(8) when said difference {X−A} is not greater than a negativediscriminating reference difference, discriminating as being a bloodsugar value increase;

(9) when said difference {X−A} is greater than said negativediscriminating reference difference but less than said positivediscriminating reference difference, discriminating as being no changein the blood sugar value;

(10) when said ratio {A/X} is not less than a second discriminatingreference ratio, discriminating as being the blood sugar value increase;and

(11) when said ratio {A/X} is greater than said first discriminatingreference ratio but less than said second discriminating referenceratio, discriminating as being no change in the blood sugar value.

In the urine sugar condition estimation method and the blood sugarcondition estimation method mentioned above, the passage “obtaining anaveraged value X of measured urine sugar values measured during a pastpredetermined period of time, always including all measured urine sugarvalues measured at the same timing in a one-day life as the timing whensaid measured urine sugar value A was measured” means that the averagedvalue X may be obtained from only all of the measured urine sugar valuesmeasured during the past predetermined period of time at the same timingin a one-day life as the timing when said measured urine sugar value Awas measured, or alternatively, from measured urine sugar valuesmeasured during the past predetermined period of time, including notonly all of the measured urine sugar values measured during the pastpredetermined period of time at the same timing in a one-day life as thetiming when said measured urine sugar value A was measured but alsomeasured urine sugar values measured during the past predeterminedperiod of time at a different timing or timings in a one-day life.Furthermore, for example, said discriminating method classificationboundary value is 50 mg/dL, and said positive discriminating referencedifference is 10 mg/dL, said negative discriminating referencedifference is −10 mg/dL, said first discriminating reference ratio is0.8, and said second discriminating reference ratio is 1.2. In addition,it is possible to select said predetermined period of time from a rangeof five days from five weeks.

Furthermore, according to this invention, there is provided a bloodsugar state estimation method, comprising the steps of:

(1) measuring a urine sugar value A;

(2) discriminating whether or not the latest HbA1c is less than adiscriminating method classification boundary value;

(3) when said latest HbA1c is less than said discriminating methodclassification boundary value, if said latest measured urine sugar valueA was measured after a meal, obtaining an averaged value X of allpost-meal measured urine sugar values measured during a pastpredetermined short period of time including the latest measured urinesugar value A and an averaged value Y of all post-meal measured urinesugar values measured during a past predetermined long period of time;(4) comparing said averaged value X of the measured urine sugar valuesmeasured during said past predetermined short period of time with saidaveraged value Y of the measured urine sugar values measured during saidpast predetermined long period of time, and discriminating that asignificant improvement is found if the ratio {X/Y} is not greater thana first reference value;(5) when said latest HbA1c is not less than said discriminating methodclassification boundary value, obtaining an averaged value X of allmeasured urine sugar values measured during said past predeterminedshort period of time including the latest measured urine sugar value Aand an averaged value Y of all measured urine sugar values measuredduring said past predetermined long period of time;(6) comparing said averaged value X of the measured urine sugar valuesmeasured during said past predetermined short period of time with saidaveraged value Y of the measured urine sugar values measured during saidpast predetermined long period of time, and discriminating that asignificant improvement is found if the ratio {X/Y} is not greater thansaid first reference value.

More particularly, the blood sugar state estimation method in accordancewith this invention, further comprises the steps of:

(7) when said ratio {X/Y} is not less than a second discriminatingreference ratio, discriminating that a significant deterioration isfound; and

(8) when said ratio {X/Y} is greater than said first discriminatingreference ratio but less than said second discriminating referenceratio, discriminating that neither the significant improvement nor thesignificant deterioration is found.

For example, said predetermined short period of time is not less thanfive days but not greater than two weeks, and said predetermined longperiod of time is at least two times said predetermined short period oftime, and is not less than two weeks but not greater than two months.Specifically, said predetermined short period of time is one week andsaid predetermined long period of time is one month. In addition, thediscriminating method classification boundary value of HbA1c is 9%.

Moreover, according to this invention, there is provided a blood sugarcondition estimation method comprising the steps of:

(1) measuring a urine sugar value A;

(2) obtaining an averaged value X of measured urine sugar values,including the latest measured urine sugar value A, measured during apast predetermined period of time at the same timing as the timing whensaid latest measured urine sugar value A was measured, and consideringthe averaged value X thus obtained as a target value;(3) comparing said target value, namely, said averaged value X with saidlatest measured urine sugar value A, and discriminating that animprovement target is achieved when the difference {X−A} is not lessthan 0 (zero).

Furthermore, according to this invention, there is provided a urinesugar meter (urine sugar measuring apparatus) including a microcomputerinstalled with a program for executing the urine sugar conditionestimation method or the blood sugar condition estimation method asmentioned above.

Also, according to this invention, there is provided a personal computerinstalled with a program for executing the urine sugar conditionestimation method or the blood sugar condition estimation method asmentioned above.

Moreover, according to this invention, there is provided a urine sugarmeter (urine sugar measuring apparatus) having a function of estimatinga urine sugar condition or a blood sugar condition, the urine sugarmeter including at least a urine sugar value measuring means, a memorymeans, a clock means, an arithmetical and control means for processinginformation, and a display means, said arithmetical and control meansoperating:

(1) at each time a urine sugar value is measured by said urine sugarvalue measuring means, to cause a measured urine sugar value A togetherwith a measurement day and time to be stored in said memory means;

(2) to obtain an averaged value X of measured urine sugar values storedin said memory means measured during a past predetermined period oftime, always including all measured urine sugar values measured at thesame timing in a one-day life as the timing when said latest measuredurine sugar value A was measured;(3) to discriminate whether or not said measured urine sugar value A isless than a discriminating method classification boundary value storedin said memory means;(4) when the measured urine sugar value A is less than thediscriminating method classification boundary value, to calculate adifference between said averaged value X and said measured urine sugarvalue A;(5) when said difference {X−A} is not less than a positivediscriminating reference difference stored in said memory means, todiscriminate as being a urine sugar value decrease or a blood sugarvalue decrease and to cause said display means to display thediscrimination;(6) when the measured urine sugar value A is not less than thediscriminating method classification boundary value, to calculate aratio between said measured urine sugar value A and said averaged valueX; and,(7) when said ratio {A/X} is not greater than a first discriminatingreference ratio stored in said memory means, to discriminate as beingthe urine sugar value decrease or the blood sugar value decrease and tocause said display means to display the discrimination.

More particularly, said arithmetical and control means further operates:

(8) when said difference {X−A} is not greater than a negativediscriminating reference difference stored in said memory means, todiscriminate as being a urine sugar value increase or a blood sugarvalue increase and to cause said display means to display thediscrimination;(9) when said difference {X−A} is greater than said negativediscriminating reference difference but less than said positivediscriminating reference difference, to discriminate as being no changein the urine sugar value or in the blood sugar value and to cause saiddisplay means to display the discrimination;(10) when said ratio {A/X} is not less than a second discriminatingreference ratio stored in said memory means, to discriminate as beingthe urine sugar value increase or the blood sugar value increase and tocause said display means to display the discrimination; and(11) when said ratio {A/X} is greater than said first discriminatingreference ratio but less than said second discriminating referenceratio, discriminating as being no change in the urine sugar value or inthe blood sugar value and to cause said display means to display thediscrimination.

For example, as mentioned hereinbefore, said discriminating methodclassification boundary value is 50 mg/dL, and said positivediscriminating reference difference is 10 mg/dL, said negativediscriminating reference difference is −10 mg/dL, said firstdiscriminating reference ratio is 0.8, said second discriminatingreference ratio is 1.2, and said predetermined period of time isselected from a range of five days from five weeks.

In addition, according to this invention, there is provided a urinesugar meter (urine sugar measuring apparatus) having a function ofestimating a blood sugar condition, the urine sugar meter including atleast a urine sugar value measuring means, a memory means, an inputmeans through which HbA1c can be inputted, a clock means, anarithmetical and control means for processing information, and a displaymeans, said arithmetical and control means causing the HbA1c inputtedthrough said input means to be stored in said memory means, saidarithmetical and control means operating:

(1) at each time a urine sugar value is measured by said urine sugarvalue measuring means, to cause a measured urine sugar value A togetherwith a measurement day and time to be stored in said memory means;

(2) to discriminate whether or not the latest HbA1c stored in saidmemory means is less than a discriminating method classificationboundary value stored in said memory means;

(3) when said latest HbA1c is less than said discriminating methodclassification boundary value, if said measured urine sugar value A wasmeasured after a meal, to calculate an averaged value X of all post-mealmeasured urine sugar values stored in said memory means measured duringa past predetermined short period of time including the latest measuredurine sugar value A, and to calculate an averaged value Y of allpost-meal measured urine sugar values measured during a pastpredetermined long period of time;(4) to compare said averaged value X of the measured urine sugar valuesmeasured during said past predetermined short period of time with saidaveraged value Y of the measured urine sugar values measured during saidpast predetermined long period of time, and to discriminate that asignificant improvement is found if the ratio {X/Y} is not greater thana first reference value stored in said memory means and to cause saiddisplay means to display the discrimination;(5) when said latest HbA1c is not less than said discriminating methodclassification boundary value, to calculate an averaged value X of allmeasured urine sugar values stored in said memory means measured duringsaid past predetermined short period of time including the latestmeasured urine sugar value A, and to calculate an averaged value Y ofall measured urine sugar values measured during said past predeterminedlong period of time;(6) to compare said averaged value X of the measured urine sugar valuesmeasured during said past predetermined short period of time with saidaveraged value Y of the measured urine sugar values measured during saidpast predetermined long period of time, and to discriminate that asignificant improvement is found if the ratio {X/Y} is not greater thansaid first reference value and to cause said display means to displaythe discrimination.

More particularly, said arithmetical and control means further operates:

(7) when said ratio {X/Y} is not less than a second discriminatingreference ratio stored in said memory means, to discriminate that asignificant deterioration is found and to cause said display means todisplay the discrimination; and

(8) when said ratio {X/Y} is greater than said first discriminatingreference ratio but less than said second discriminating referenceratio, to discriminate that neither the significant improvement nor thesignificant deterioration is found and to cause said display means todisplay the discrimination.

As mentioned hereinbefore, said predetermined short period of time isnot less than five days but not greater than two weeks, and saidpredetermined long period of time is at least two times saidpredetermined short period of time, and is not less than two weeks butnot greater than two months. Specifically, said predetermined shortperiod of time is one week and said predetermined long period of time isone month. In addition, the discriminating method classificationboundary value of HbA1c is 9%.

In addition, according to this invention, there is provided a urinesugar meter (urine sugar measuring apparatus) having a function ofestimating a blood sugar condition, the urine sugar meter including atleast a urine sugar value measuring means, a memory means, a clockmeans, an arithmetical and control means for processing information, anda display means, said arithmetical and control means operating:

(1) at each time a urine sugar value is measured by said urine sugarvalue measuring means, to cause a measured urine sugar value A togetherwith a measurement day and time to be stored in said memory means;

(2) to calculate an averaged value X of measured urine sugar valuesstored in said memory means, including the latest measured urine sugarvalue A, measured during a past predetermined period of time at the sametiming as the timing when said measured urine sugar value A wasmeasured, and to consider the averaged value X thus obtained as a targetvalue;(3) to compare said target value, namely, said averaged value X with thelatest measured urine sugar value A, and to discriminate that animprovement target is achieved when the difference {X-A} is not lessthan 0 (zero).

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is an appearance view of a conventional urine sugar meter in aseparated condition;

FIG. 2 is an appearance view of the conventional urine sugar meter in arepository condition;

FIG. 3 is a block diagram showing an electronic construction of theconventional urine sugar meter;

FIG. 4 is a view illustrating a display condition in a display sectionof the urine sugar meter shown in FIG. 1;

FIG. 5 is a flowchart illustrating the procedure of the blood sugarcondition estimation method in accordance with the Embodiment 1 and theEmbodiment 2 of this invention;

FIG. 6 is a flowchart illustrating the procedure of the blood sugarcondition estimation method in accordance with the Embodiment 4 of thisinvention;

FIG. 7 is a graph showing an experimental data, testifying the bloodsugar condition estimation method in accordance with the Embodiment 4 ofthis invention;

FIG. 8 is a flowchart illustrating the procedure of the blood sugarcondition estimation method in accordance with the Embodiment 5 of thisinvention; and

FIG. 9 is a block diagram illustrating a connection between the urinesugar meter and a personal computer.

EMBODIMENTS

One embodiment of the blood sugar condition estimation method andapparatus for carrying out this invention is an improvement of the urinesugar meter (urine sugar measuring apparatus) disclosed in the abovementioned Patent Document 2, as one example of biochemistry measuringinstrument, configured to detect the urine sugar by use of an action ofenzyme. Accordingly, a fundamental construction and function are thesame as the urine sugar meter disclosed in the above mentioned PatentDocument 2. Thus, the contents of Patent Document 2 are incorporated byreference in its entirety into this application, and a detaileddescription will be omitted.

FIGS. 1 and 2 are an appearance view, FIG. 3 is a block diagramillustrating an electrical construction, and FIG. 4 is a partialenlarged view showing the display form of a display section.

As shown in FIG. 1, the shown urine sugar meter (urine sugar measuringapparatus) 1 comprises a sensor cartridge 11 for electrochemicallydetecting sugar in the urine, and a meter main body 21 which serves as agrip for holding the urine sugar meter during measurement and whichmeasures and displays the concentration of sugar in the urine based onthe detection made by the sensor cartridge 11. In order to make thesensor cartridge 11 exchangeable, the sensor cartridge 11 and the metermain body 21 can be separated from each other as shown in FIG. 1 and canbe coupled with each other as shown in FIG. 2. Incidentally, as shown inFIG. 1, the urine sugar meter 1 is so configured that the urine sugarmeter 1 can be inserted and stored in a stand 41 having a magnet 42,when it is not used.

The sensor cartridge 11 comprises a urine sugar sensor 13, a thermistor14, a stand detection reed switch 15, a connector 16, and a connectorconnection detection circuit 17, as shown in the block diagram of FIG.3, which are accommodated within a housing 12 shown in FIG. 1. Inaddition, the meter main body 21 comprises a power supply 23, operationbuttons 24 (24 a, 24 b), a D/A (digital-to-analog) converter 25, asensor driving circuit 26, an A/D (analog-to-digital) converter 27, abuzzer 28, a LCD (liquid crystal display) display 29, an external I/O(input-output) interface terminal 30, a connector 31, and amicrocomputer 32, which are accommodated within a housing 22.

The urine sugar sensor 13 has a lifetime, and when it reaches a uselimit, a “sensor exchange” is indicated in the LCD display 29. In such acase, a user detaches the sensor cartridge 11 from the meter main body21, and attaches a new sensor cartridge 11 to the meter main body 21.The sensor cartridge 11 and the meter main body 21 are then electricallyinterconnected, and therefore, it is preferred that when the sensorcartridge 11 is exchanged, it is possible to easily connect theconnector 16 of the sensor cartridge 11 to the connector 31 of the metermain body 21. Additionally, since the sensor cartridge 11 is bathed withurine and a washing water, a boundary between the sensor cartridge 11and the meter main body 21 has to be excellent in a waterproof property,and the waterproof property has to be always maintained irrespectivelyof how many time it is exchanged.

When the life of the battery contained in the meter main body 21 hasterminated, it is necessary to replace the battery with a new battery.Therefore, attention should be preferably paid so that the user caneasily make the exchange of battery. That is to say, it is preferredthat the battery can be easily taken out from the meter main body 21 andthen the new battery can be easily mounted in the meter main body 21.

The urine sugar sensor 13 detects the concentration of sugar in theurine over a wide range from a low level to a middle level and to a highlevel, while excluding the influence of foreign substances in the urine.The urine sugar sensor 13 is to utilize enzyme as a sensor for theurinary constituent detection. The thermistor 14 detects the temperatureof the urine at the time of measurement in order to compensate for thetemperature characteristics of the urine sugar sensor 13.

When the urine sugar meter 1 is located in the stand 41, the standdetecting reed switch 15 is put in an OFF condition (or, ON condition)by action of a magnetic field of the magnet 42. Recognizing the OFFcondition (or, ON condition) of the stand detecting reed switch 15, themicrocomputer 32 puts the LCD display 29 into an OFF condition in orderto reduce an electric power consumption to the utmost, and also, themicrocomputer 32 itself becomes a sleep condition, excepting for acounting function and a function for monitoring the stand detecting reedswitch 15. If the urine sugar meter 1 is taken out from the stand 41,the stand detecting reed switch 15 is moved out of the extent of theinfluence of the magnetic field of the magnet 42, with the result thatthe stand detecting reed switch 15 is put into the ON condition (or, OFFcondition). Recognizing the ON condition (or, OFF condition) of thestand detecting reed switch 15, the microcomputer 32 recovers all thefunctions of the urine sugar meter so that a mode setting, calibrationand the measurement of the urinary sugar concentration become possible.

The power supply 23 is a battery and supplies an electric power tovarious electrical systems of the urine sugar meter 1. The operationbuttons 24 (24 a and 24 b) detect a depression thereof, and are used bya user to select, set and register a mode or a meal menu or correct ameal menu. The D/A converter 25 converts a digital signal (drivingsignal) from the microcomputer 32 into an analog signal (drivingsignal), and outputs the analog signal thus obtained. On the basis ofthe driving signal from the D/A converter 25, the sensor driving circuit26 supplies a driving signal to the urine sugar sensor 13, and receivesa detection signal detected by the urine sugar sensor 13 to supply thereceived detection signal to the A/D converter 27.

The A/D converter 27 converts the analog signal (detection signal) fromthe sensor driving circuit 26 into a digital signal (detection signal),and outputs the digital signal thus obtained. On the basis of a signalfrom the microcomputer 32, the buzzer 28 generates a buzzer sound fornotifying a start of the urine sugar measurement, for example. Based ona signal from the microcomputer 32, the LCD display 29 displays thestatus of the calibration, the status of the measurement, thenotification of the sensor exchange, the notification of the batteryexchange, the status of the selection mode, a preliminary announcementof the next measurement, the indication of the result of the urine sugarmeasurement, and the notification of the result of the discrimination.

More specifically, the display 29 displays the status of calibration bylighting the “reference matching (base matching)” and the “dropletmarks” of display items shown in FIG. 4 at the time of calibration.Further, the display 29 displays the status of measurement by lightingany of “standby”, “measuring”, “cleaning” and “done” in the course ofthe measurement. Also, the display 29 displays the notification ofreplacement of the sensor cartridge 11 by lighting the “sensorreplacement” when the urine sugar sensor 13 is to be replaced. Inaddition, the display 29 displays the notification of replacement of thebattery by lighting the “battery mark” when the battery is to bereplaced. Further, the display 29 displays the status of selected modeby lighting the “mode” and a selected one of “1”, “2”, “3” and “4”adjacent to the “mode” at the time of event, in order to indicate thestatus of the selected mode. Also, the display 29 displays thepreliminary announcement of the next measurement by lighting the “nextmeasurement” and “hours later”, and “1” or “2” therebetween at the timeof event. Further, the display 29 displays the indication of the urinesugar measurement result by lighting a urine sugar change value, areference urine sugar change value or a normal urine sugar change valuein “4-digit number” exemplified as “1347” at the center of the drawing,after measurement, respectively. Further, the display 29 displays thestatus of the selected mode by lighting one of three “triangle marks”which corresponds in position to one of discrimination contents printedon the housing 22 after each discrimination.

In addition, one of “decrease”, “no change” and “increase” is litdepending upon whether the urine sugar value decreases, does not change,or increases.

The external input-output interface terminal 30 is to connect theexternal input-output interface 38 in the microcomputer 32 with anexternal apparatus such as a personal computer or the like (shown in theconceptual view of FIG. 9), in order to enable communication of variousdata (input data from the external apparatus, and output data such as aurine sugar measurement result and a discrimination result from theurine sugar meter 1) between the microcomputer 32 and the externalapparatus. The connector 16 and 31 electrically interconnect between thesensor cartridge 11 and the meter main body 21. The connector connectiondetecting circuit 17 detects whether the connectors 16 and 31 aremaintained in a connection condition.

Similarly to Patent Document 2 mentioned hereinbefore, the microcomputer32 comprises an arithmetic and control unit 33 for executing variousurine sugar value computations and various “good or bad” discriminationsand for performing various controls, a ROM 34 for storing programs forcontrols and computations, a RAM 35 for temporarily storing thecomputation results, programs read from an external device, and thelike, a clock 36 for generating a clock signal for variousnotifications, an auxiliary memory 37 for storing the selected mode, themeal menus, various computed urine sugar values and variousdiscrimination results until they are updated, an external I/O interface38 for communicating various data (i.e. input data from an externaldevice and output data such as urine sugar measurement results anddiscrimination results from the urine sugar meter 1) between an externaldevice such as a personal computer and the urine sugar meter 1, andvarious ports (not shown) connected to various electrical systems. Themicrocomputer 32 notifies a user that an immediately-before-meal urinesugar value, an after-meal urine sugar value, a reference before-mealurine sugar value, a reference after-meal urine sugar value, a normalbefore-meal urine sugar value and a normal after-meal urine sugar valueshould be measured. The microcomputer 32 also performs measurement ofthe before-meal urine sugar value, the immediately-before-meal urinesugar value, the after-meal urine sugar value, the reference before-mealurine sugar value, the immediately-before-meal urine sugar value, thereference after-meal urine sugar value, the normal before-meal urinesugar value, a normal immediately-before-meal urine sugar value and thenormal after-meal urine sugar value. The microcomputer 32 furtherperforms computation of a urine sugar change value (difference betweenthe after-meal urine sugar value and the immediately-before-meal urinesugar value), a reference urine sugar change value (difference betweenthe reference after-meal urine sugar value and the referenceimmediately-before-meal urine sugar value), a normal urine sugar changevalue (difference between the normal after-meal urine sugar value andthe normal immediately-before-meal urine sugar value), and a mealdifference urine sugar change value (difference between the normal urinesugar change value and the reference urine sugar change value), Themicrocomputer 32 also discriminates on the basis of the urine sugarchange value whether a change in sugar amount within a body of a humanbeing is good or bad, and discriminates on the basis of the mealdifference urine sugar change value whether the content of the normalmeal menu is good or bad. Furthermore, the microcomputer 32 performsprocessing such as a control of the output of the results of thecomputations and the discriminations as mentioned above.

In addition, according to this invention, the microcomputer 32discriminates on the basis of the latest measurement result of the urinesugar value whether the blood sugar value decreases, does not change orincreases, and then, lights one of the “decrease”, “no change” and“increase” of the display unit, based on the result of thediscrimination.

Now, an operation of this invention will be described. But, since themeasuring method itself of the urine sugar value and the method forobtaining the various values mentioned above are explained in detail inPatent Documents 1 and 2 mentioned hereinbefore, the contents of PatentDocuments 1 and 2 are incorporated by reference in its entirety intothis application, and a detailed description will be omitted.

Embodiment 1 Comparison and Discrimination with One-Week Average

By comparing the latest measured urine sugar value with measured urinesugar values in the past one week, whether the latest blood sugarcondition is good or bad is discriminated. FIG. 5 is a flowchart of theprocedure of Embodiment 1. However, since the procedure of Embodiment 1is the same as the procedure of Embodiment 2 which will be describedhereinafter, what should be indicated as “Xw” in Embodiment 1 and whatshould be indicated as Xm in Embodiment 2 are indicated merely as “X” inthe flowchart of FIG. 5. The urine sugar meter 1 stores the measuredurine sugar data in at least the past one week together with respectivemeasurement timings in the auxiliary memory 37 of the microcomputer 32.

By using the urine sugar meter 1 and by pushing a measurement startbutton on the urine sugar meter 1, the urine sugar is measured. Themicrocomputer 32 of the urine sugar meter 1 stores the measurementtiming together with the measurement data in the auxiliary memory 37.

First of all, the microcomputer 32 discriminates whether or note thelatest measured urine sugar value A is less than 50 mg/dL.

When the latest measured urine sugar value A is less than 50 mg/dL, themicrocomputer 32 reads out all measured urine sugar values in the pastone week at the same timing (such as before-meal or after-meal) in aone-day life as the timing when the latest measured urine sugar value Awas measured (here, the same timing should be considered not to requirethe accuracy in units of minute, such as how many minutes before orafter meal, and this will be applied in the following descriptions).Furthermore, the microcomputer 32 calculates an averaged value Xw of theread-out measured urine sugar values in the past one week, and then,calculates a difference between the one-week averaged value Xw and thelatest measured urine sugar value A, namely, {Xw−A}, and furtherdiscriminates whether or not {Xw−A} is not less than 10 mg/dL andwhether or not {Xw−A} is not greater than −10 mg/dL.

When {Xw−A} is not less than 10 mg/dL, the “decrease” of the display islit. When {Xw−A} is not greater than −10 mg/dL, the “increase” of thedisplay is lit. Otherwise, namely, when −10 mg/dL<{Xw−A}<10 mg/dL, the“no change” of the display is lit.

When the latest measured urine sugar value A is not less than 50 mg/dL,the microcomputer calculates the ratio between the latest urine sugarvalue A and the one-week averaged value Xw obtained as mentioned above(namely, A/Xw), and then, discriminates whether or not {A/Xw} is notgreater than 0.8 and whether or not {A/Xw} is not less than 1.2.

When {A/Xw} is not greater than 0.8, the “decrease” of the display islit. When whether or not {A/Xw} is not less than 1.2, the “increase” ofthe display is lit. Otherwise, namely, when 0.8<{A/Xw}<1.2, the “nochange” of the display is lit.

Embodiment 2 Comparison and Discrimination with One-Month Average

By comparing the latest measured urine sugar value with measured urinesugar values in the past one month, whether the latest blood sugarcondition is good or bad is discriminated. As mentioned hereinbefore,the procedure is the same as the flowchart of the procedure ofEmbodiment 1 as shown in FIG. 5.

In case of this Embodiment 2, the urine sugar meter 1 stores themeasurement data of the urine sugar value in at least the past one monthtogether with respective measurement timings in the auxiliary memory 37of the microcomputer 32. By using the urine sugar meter 1 and by pushingthe measurement start button of the urine sugar meter 1, the urine sugaris measured. The microcomputer 32 of the urine sugar meter 1 stores themeasurement timing together with the measurement data in the auxiliarymemory 37.

First of all, the microcomputer 32 discriminates whether or note thelatest measured urine sugar value A is less than 50 mg/dL.

When the latest measured urine sugar value A is less than 50 mg/dL, themicrocomputer 32 reads out all measured urine sugar values in the pastone month at the same timing in a one-day life as the timing when thelatest measured urine sugar value A was measured, and then, calculates aone-month averaged value Xm. The microcomputer 32 calculates adifference between the one-month averaged value Xm and the latestmeasured urine sugar value A, namely, {Xm−A}, and further discriminateswhether or not {Xm−A} is not less than 10 mg/dL and whether or not{Xm−A} is not greater than −10 mg/dL.

When {Xm−A} is not less than 10 mg/dL, the “decrease” of the display islit. When {Xm−A} is not greater than −10 mg/dL, the “increase” of thedisplay is lit. Otherwise, namely, when −10 mg/dL<{Xm−A}<10 mg/dL, the“no change” of the display is lit.

When the latest measured urine sugar value A is not less than 50 mg/dL,the microcomputer calculates the ratio between the latest urine sugarvalue A and the one-month averaged value Xm obtained as mentioned above(namely, A/Xm), and then, discriminates whether or not {A/Xm} is notgreater than 0.8 and whether or not {A/Xm} is not less than 1.2.

When {A/Xm} is not greater than 0.8, the “decrease” of the display islit. When whether or not {A/Xm} is not less than 1.2, the “increase” ofthe display is lit. Otherwise, namely, when 0.8<{A/Xm}<1.2, the “nochange” of the display is lit.

In Embodiment 1 and Embodiment 2 mentioned above, when the latest urinesugar value is less than 50 mg/dL, the discrimination is carried out byobtaining the difference between the latest measured value and theaveraged value in the past, and when the latest urine sugar value is notless than 50 mg/dL, the discrimination is carried out by obtaining theratio between the latest measured value and the averaged value in thepast. However, the boundary value of the urine sugar value forclassifying the discriminating method is in no way limited to 50 mg/dL.In addition, in Embodiment 2, the one-month averaged value Xm isobtained by reading out all the measured urine sugar values in the pastone month at the same timing in a one-day life as the timing when thelatest measurement was performed. However, it is possible to obtain theone-month averaged value Xm by reading out all the measured urine sugarvalues in the past one month, if the read-out measured urine sugarvalues includes all the measured urine sugar values in the past onemonth at the same timing in a one-day life as the timing when the latestmeasurement was performed, even if the read-out measured urine sugarvalues includes measured urine sugar values obtained at other timings.The reason for this is that the influence of variation in measured urinesugar values attributable to different measurement timings is consideredto be slight.

The urine sugar value takes the wide value from a value less than 50mg/dL to a value reaching thousands mg/dL. When the urine sugar value isless than 50 mg/dL, whether or not the difference between the latestmeasured value and the averaged value of the past measured values isless than 10 mg/dL has an important meaning, but in the case that theurine sugar value reaches thousands mg/dL, if the difference between thelatest measured value and the averaged value of the past measured valuesis less than 10 mg/dL, the difference would be negligible in view ofsignificant digites. Accordingly, when the urine sugar value is large,considering the case of performing the discrimination on the basis ofthe difference between the latest measured value and the averaged valueof the past measured values, it would be necessary to classify,depending upon the magnitude of the measured urine sugar value, thedifference that becomes the reference for discriminating whether it isimprovement or deterioration, for example into a first case that themeasured urine sugar value is 50 mg/dL to 100 mg/dL, a second case thatthe measured urine sugar value is 100 mg/dL to 300 mg/dL, a third casethat the measured urine sugar value is 300 mg/dL to 1000 mg/dL, a fourthcase that the measured urine sugar value is 1000 mg/dL to 3000 mg/dL,and a fifth case that the measured urine sugar value is not less than3000 mg/dL. This is very troublesome. Therefore, the 50 mg/dL of thediscriminating method classification boundary value in Embodiment 1 andin Embodiment 2 is not a critical value.

In the case of adopting the two different discriminating methods as inEmbodiment 1 and Embodiment 2, the discriminating method classificationboundary value of the urine sugar value can be selected from the rangeof 30 mg/dL to 100 mg/dL. In addition, the difference that becomes thereference for discriminating whether it is improvement or deterioration,can be varied, depending upon the discriminating method classificationboundary value of the urine sugar value. However, it is now consideredto have the highest validity that the discriminating methodclassification boundary value of the urine sugar value is 50 mg/dL andthe difference that becomes the reference for discriminating whether itis improvement or deterioration, is 10 mg/dL.

Embodiment 3 Estimation Method of the Urine Sugar Condition

The control of health condition is required by not only diabetics butalso humans being who are not a diabetic. Apart from the correlationamong the blood sugar value, HbA1c and the urine sugar value, a rise ofthe urine sugar value is not desirable for not only diabetics but alsohealthy humans being. However, there is a dispersion in the measuredvalue of the urine sugar value, namely, in the instantaneous value ofthe urine sugar value, and in particular, the urine sugar value greatlychanges depending upon the content of meal. Therefore, the urine sugarvalue does not directly become an index of the health condition. Assuch, it is difficult to grasp from a one-time measurement a “variationin time in a long or middle span” which can constitute a substantiallyhealth index. Furthermore, since the instantaneous value of the urinesugar value has a large dispersion as mentioned above, even if the urinesugar values are simply plotted in a graph over a long or middle span,it is difficult to grasp the variation in time of the urine sugarvalues, and therefore, it is not sufficient as the health index. From adifferent viewpoint, it is required for not only diabetics but alsohealthy humans being, to know whether or the health condition is now inan improving tendency or in a deteriorating tendency from the viewpointof a relatively longe span, not becoming optimistic or pessimisticdependently upon the urine sugar value obtained from a one-timemeasurement. Examining the methods of Embodiment 1 and Embodiment 2mentioned above from this viewpoint, if the urine sugar value isdiscriminated in accordance with the methods of Embodiment 1 andEmbodiment 2, it will become an indication of the health condition.Accordingly, the above mentioned blood sugar condition estimation methodwill become a urine sugar condition estimation method withoutmodification.

Embodiment 4 HbA1c Estimation

The urine sugar meter 1 is so configured to connect to an externalpersonal computer, as shown in the conceptual scheme of FIG. 9.Therefore, the urine sugar meter 1 can be connected with the personalcomputer, and by operating the personal computer, HbA1c can be writtenand stored in the auxiliary memory 37 of the microcomputer 32 of theurine sugar meter. This facilitates to compare between HbA1c and theurine sugar value. In the meanwhile, the urine sugar meter 1 stores themeasurement data of the urine sugar value in at least the past one monthtogether with respective measurement timings in the auxiliary memory 37of the microcomputer 32.

FIG. 6 is a flowchart of the procedure for estimating whether or HbA1cis in an improving tendency in a deteriorating tendency, by comparingthe present blood sugar condition considered from the urine sugar valuewith the past blood sugar condition considered from the urine sugarvalues.

First of all, after HbA1c is measured, the urine sugar meter 1 isconnected with the personal computer, and HbA1c is written and iswritten and stored in the auxiliary memory 37 of the microcomputer 32 ofthe urine sugar meter, by operating the personal computer.

In the meanwhile, the measurement data of the urine sugar values in atleast the past one month before the latest HbA1c was written in theauxiliary memory 37 of the microcomputer 32 is stored together withrespective measurement timings in the auxiliary memory 37 of themicrocomputer 32.

(1) At each time urine sugar value is measured by the urine sugar meter1, the measurement result A is stored in the auxiliary memory 37 of themicrocomputer 32.

(2) At each time the urine sugar value measurement result A is stored inthe auxiliary memory 37 of the microcomputers 32, whether or not thelatest HbA1c stored in the auxiliary memory 37 is less than 9% isdiscriminated. If the latest HbA1c is less than 9%, whether or not thelatest measurement result A of the urine sugar value is an after-mealdata is discriminated. If the latest measurement result A is not anafter-meal data, the processing terminates. The following is the reasonwhy the processing terminates if the latest measurement result A is notan after-meal data. In the case that HbA1c is less than 9%, it is thepresent situation that it is not possible to find out a significantcorrelation between HbA1c and the urine sugar value measured in acondition other than the after-meal.

If the latest measurement is after-meal, all after-meal measured urinesugar values obtained during a past predetermined short period of time,for example, during the past one week, including the latest measurementresult A of the urine sugar value, are read out and then an averagedvalue X is calculated. Furthermore, all after-meal measured urine sugarvalues obtained during a past predetermined long period of time, forexample, during the past one month, are read out and then an averagedvalue Y is calculated. By comparing the averaged value X of the measuredvalues obtained during the past predetermined short period of time (pastone week) with the averaged value Y of the measured values obtainedduring the past predetermined long period of time (past one month), aratio {X/Y} is calculated. When the ratio X/Y is not greater than 0.5,it is discriminated that HbA1c was improved not less than apredetermined value, for example, not less than 0.5%. On the other hand,when the ratio X/Y is not less than 2, it is discriminated that HbA1cwas deteriorated not less than a predetermined value, for example, notless than 0.5%. In the case of 0.5<{X/Y}<2, it is considered that thechange is less than 0.5%, and therefore, it is discriminated that thereis neither significant improvement nor significant deterioration.

(4) If the latest HbA1c is not less than 9%, irrespectively of whetheror not the latest measurement result A of the urine sugar value is anafter-meal data, all measured urine sugar values obtained during a pastpredetermined short period of time, for example, during the past oneweek, are read out and then an averaged value X is calculated.Furthermore, all measured urine sugar values obtained during a pastpredetermined long period of time, for example, during the past onemonth, are read out and then an averaged value Y is calculated. Bycomparing the averaged value X of the measured values obtained duringthe past predetermined short period of time (past one week) with theaveraged value Y of the measured values obtained during the pastpredetermined long period of time (past one month), a ratio {X/Y} iscalculated. When the ratio X/Y is not greater than 0.5, it isdiscriminated that HbA1c was improved not less than a predeterminedvalue, for example, not less than 0.5%. On the other hand, when theratio X/Y is not less than 2, it is discriminated that HbA1c wasdeteriorated not less than a predetermined value, for example, not lessthan 0.5%. In the case of 0.5<{X/Y}<2, it is considered that the changeis less than 0.5%, and therefore, it is discriminated that there isneither significant improvement nor significant deterioration.

FIG. 7 is the experimental data which has verified the Embodiment 3mentioned above. The graph of FIG. 7 illustrates the urine sugar valuesof a reagent measured after every meals over about two months, and HbA1c(%) measured monthly (three times for two months) in time sequence (theaxis of ordinates:the urine sugar values and HbAc, and the axis ofabscissas:day).

In addition, a lower portion of FIG. 7 explains the validity of theestimation concluding from comparison of the urine sugar values thatHbA1c (%) was improved in a first one month and in a second one month ofthe two-month measurement period, respectively.

That is to say, from the measured values of the urine sugar valuemeasured during the first one month, it is observed that the averagedvalue Y for the one month concerned is 99.9 (mg/dL), and the averagedvalue X for the final one week of the one month concerned is 47.9(mg/dL). According to the Embodiments 3 of this invention, since[47.9<(99.9/2)], hence, since the averaged value X is not greater than ½of the averaged value Y, it is discriminated that HbA1c (%) was improvednot less than 0.5%. Here, focusing the actual measured value of HbA1c(%), the HbA1c (%) has decreased from 8.7% to 7.4%, namely, HbA1c (%)was improved not less than 0.5%. This verifies the validity of theEmbodiment 3.

In the second one month, it can be said to be similar. That is to say,from the measured values of the urine sugar value measured during thesecond one month, it is observed that the averaged value Y for the onemonth concerned is 36.3 (mg/dL), and the averaged value X for the finalone week of the one month concerned is 16.6 (mg/dL). According to theEmbodiments 3 of this invention, since [16.6<(36.3/2)], hence, since theaveraged value X is not greater than ½ of the averaged value Y, it isdiscriminated that HbA1c (%) was improved not less than 0.5%. Here,focusing the actual measured value of HbA1c (%), the HbA1c (%) hasdecreased from 7.4% to 6.6%, namely, HbA1c (%) was improved not lessthan 0.5%. This also verifies the validity of the Embodiment 3.

Here, in order to verify from comparison of the monthly measured HbA1c(%) (three times for two months), the actual measured value of HbA1c (%)was examined by dividing the two months into a first one month and asecond one month. However, it would be understood from the explanationof the Embodiment 3 mentioned above that attention is not necessarilypaid to only one month before the measurement date of HbA1c in theEmbodiment 3. For example, when the urine sugar value was measured onAug. 11, 2008 in the graph of FIG. 7, the HbA1c estimation is carriedout from the measured values of the urine sugar values in one week andin one month just before Aug. 11, 2008. The averaged value Y for onemonth before Aug. 11, 2008 is 64.2 (mg/dL), and the averaged value X forone week before Aug. 11, 2008 is 36.6 (mg/dL). According to Embodiment 3of this invention, since [(64.2/2)<36.6<2(64.2)], hence, the averagedvalue X is greater than ½ of the averaged value Y but less than twotimes the averaged value Y. Therefore, it is discriminated that thechange is not greater than 0.5%, namely, that there is neithersignificant improvement nor significant deterioration.

In the graph of FIG. 7, if the HbA1c estimation was carried out everyday after a daily measurement of the urine sugar value during the secondone month, there is obtained either the discrimination result that“HbA1c (%) was improved not less than 0.5%” or the discrimination resultthat “there is neither significant improvement nor significantdeterioration”. Accordingly, a diabetic can recognize that HbA1c is inan improving tendency. It could be seen that this recognition isconsistent with the change of the measured value of HbA1c.

In Embodiment 3 mentioned above, the predetermined long period of timeand the predetermined short period of time are one month and one week,respectively, but, are not limited to those specific periods of time.Generally, since the averaged value of the blood sugar values over oneto two months is considered to indicate the blood sugar condition whichis not influenced by a temporary change caused by meal and others, thepredetermined long period of time is preferably set within the range ofover one to two months, as a period presenting the urine sugar conditioncorresponding to the blood sugar condition. On the other hand, thepredetermined short period of time corresponds to a period whichpresents a recent blood sugar condition but absorbs daily extremevariations. Therefore, the predetermined short period of time ispreferably set within a range of not greater than one month, and isrequired to be sufficiently shorter than the predetermined long periodof time. Accordingly, the predetermined short period of time issufficiently shorter than the predetermined long period of time and ispreferred to be at least not shorter than five days but not longer thantwo weeks. The predetermined long period of time is longer than at leasttwo times the predetermined short period of time, and can be arbitrarilyselected from the range of not shorter than two weeks but not longerthan two months.

In addition, as regards the degree of improvement of the estimated HbA1c(%), the improvement of HbA1c of not less than a predetermined value isexemplified as the improvement of HbA1c of not less than 0.5%”. However,this predetermined value is in no way limited to 0.5%, but may be anyvalue which can be considered to show a significant improvement.

Furthermore, in the above mentioned embodiment, whether the extent ofmeasured values for obtaining the averaged value is limited to only theafter-meal measured values or includes all the measured values, isdetermined depending upon whether or not the latest HbA1c is less than9%. However, this is based on the result of research of the inventor ofthis invention that when the boundary value of HbA1c was 9%, the resultof discrimination is the highest in validity. Therefore, it is notabsolute that the boundary value of HbA1c is 9%. Accordingly, it isconsidered that even if the boundary value of HbA1c is changed to avalue larger or smaller than 9% but near to 9%, the validity of theresult of discrimination will never abruptly drop. Therefore, theboundary value of HbA1c can be changed to a value larger or smaller than9% but near to 9%,

Embodiment 5 Target Value Setting Function

In order to improve HbA1c (blood sugar condition, lifestyle habit), animprovement target is set, and whether or not the improvement target hasbeen achieved is discriminated from the latest (recent) urine sugardata.

For example, when an improvement target is set to be an improvement ofHbA1c of not less than 0.5%, the improvement target value is set to ahalf of an averaged value of urine sugar values in the past one month(measured at the same timing as the timing of the latest measurement)including the latest measured value. The latest measured value iscompared with the improvement target value, and when the latest measuredvalue exceeds the improvement target value, it is notified by forexample a lamp or an alarm. Here, the one month is a predeterminedperiod of time, which is in no way limited to the one month but can bearbitrarily selected from the range of not less than two weeks but notgreater than two months.

FIG. 8 is a flowchart illustrating the procedure of Embodiment 4 (targetvalue setting function).

First of all, the improvement target, for example, “improvement of HbA1cof not less than 0.5%”, is written and stored in the auxiliary memory 37of the microcomputer 32 of the urine sugar meter.

In the meanwhile, the measurement data of the urine sugar values of atleast the past one month is stored together with respective measurementtimings in the auxiliary memory 37 of the microcomputer 32.

(1) At each time the urine sugar is measured by the urine sugar meter 1,the measurement result A is stored in the auxiliary memory 37 of themicrocomputer 32.

At each time the measurement result A of the urine sugar value is storedin the auxiliary memories 37 of the microcomputers 32, urine sugarmeasured values in the past one week including the latest measurementresult A of the urine sugar value and measured for example at the sametiming as the timing of the latest measurement result A of the urinesugar value, are read out, and an averaged value X is calculated, sothat the averaged value X thus obtained is set as a target value. Thelatest measurement result A of the urine sugar value is compared withthe target value, namely, the averaged value X thus obtained. If {X−A}is not less than 0 (zero), the “decrease” of the display unit of FIG. 4is lit in order to indicate the achievement of the improvement target,“OK”. Otherwise, both of “no change” and “increase” of the display unitof FIG. 4 are lit or blinked as “caution lamp”.

In all the above mentioned embodiments, the data processing is carriedout in the urine sugar meter itself. However, it is a matter of coursethat it is possible to carry out the data processing and to display theresult of the date processing in a personal computer connected to theurine sugar meter. For example, as shown in FIG. 9, at each measurement,the urine sugar meter is connected with the personal computer, and themeasured value and its measurement date and time data are transferred tothe personal computer so as to be stored in a memory of the personalcomputer. In the meanwhile, when HbA1c was measured, the value of HbA1cand its measurement date and time data are inputted into the personalcomputer so as to be stored in a memory of the personal computer. Aprogram previously installed in the personal computer for carrying outthe procedures of Embodiments 1 to 4 mentioned above, is selectivelyexecuted so that the result of the procedures of Embodiments 1 to 4 canbe obtained by use of the personal computer. This will be apparent toaveraged persons skilled in the art with no necessity of explanation.

As described above, the blood sugar condition estimation method andapparatus of this invention has the function to store a measured urinesugar value and the value of HbA1c inputted together with itsmeasurement date and time, and can carry out the discrimination of theblood sugar condition and the estimation of HbA1c, etc. on the basis ofa non-invasive urine sugar measurement.

Specifically, the blood sugar condition estimation method and apparatusof this invention can discriminate the improvement or deterioration ofHbA1c by comparing the measured urine sugar value with past measuredurine sugar values.

In addition, the blood sugar condition estimation method and apparatusof this invention can discriminate, on the basis of the measured urinesugar value, whether or not the present lifestyle improving effort willlead to the improvement of HbA1c.

Furthermore, the blood sugar condition estimation method and apparatusof this invention can calculate a urine sugar target value from themeasured urine sugar value and the improvement target value of HbA1c.

Since the blood sugar condition estimation method and apparatus of thisinvention stores a measured urine sugar value and the value of HbA1cinputted, it is possible to easily select out the discrimination, theestimation and the setting of the target value, which can be obtained byutilizing the stored data. In addition, for the discrimination, theestimation and the setting of the target value, an optimum calculationmethod can be selected from the purpose, the stage of diabetes of theuser, the life pattern, etc.

Therefore, just after the measurement, the blood sugar conditionestimation method and apparatus of this invention can discriminate a“good or bad” in connection with meal, exercise, etc. just before themeasurement, and also, can estimate the improving tendency of HbA1c.Furthermore, since the improvement target can be set, it is possible tosustain the user's motivation for the user's blood sugar control.

Moreover, if the urine sugar meter, which is the blood sugar conditionestimation method and apparatus of this invention, is added withcommunication means, it is possible to combine with data obtained byfurther various external instruments (for example, the record of bodyweight, meal and exercise, etc.), with the result that the reliabilityof the discrimination, the estimation and the target setting iselevated.

Furthermore, if the data obtained is accumulated into a server throughInternet, etc., the reliability of the discrimination, the estimationand the target setting is elevated. If the urine sugar meter standsalone, those are calculated on the basis of the data of only the singleuser. If the urine sugar meter is connected to an external server, sinceall data of the urine sugar meter's users is accumulated, even if thedata of only the single user is less, the estimation becomes easy sothat the reliability of the discrimination is elevated.

The invention claimed is:
 1. A urine sugar condition estimation method,comprising the steps of: (1) measuring a urine sugar value A; (2)obtaining an averaged value X of measured urine sugar values measuredduring a past predetermined period of time, always including allmeasured urine sugar values measured at the same timing in a one-daylife as the timing when said latest measured the urine sugar value A ismeasured; (3) discriminating whether or not said measured urine sugarvalue A is less than a discriminating method classification boundaryvalue; (4) when the measured urine sugar value A is less than thediscriminating method classification boundary value, calculating adifference between said averaged value X and said measured urine sugarvalue A; (5) when said difference {X−A} is not less than a positivediscriminating reference difference, discriminating as being a urinesugar value decrease; (6) when the measured urine sugar value A is notless than the discriminating method classification boundary value,calculating a ratio between said measured urine sugar value A and saidaveraged value X; and, (7) when said ratio {A/X} is not greater than afirst discriminating reference ratio, discriminating as being the urinesugar value decrease.
 2. A urine sugar condition estimation methodclaimed in claim 1, further comprises the steps of: (8) when saiddifference {X−A} is not greater than a negative discriminating referencedifference, discriminating as being a urine sugar value increase; (9)when said difference {X−A} is greater than said negative discriminatingreference difference but less than said positive discriminatingreference difference, discriminating as being no change in the urinesugar value; (10) when said ratio {A/X} is not less than a seconddiscriminating reference ratio, discriminating as being the urine sugarvalue increase; and (11) when said ratio {A/X} is greater than saidfirst discriminating reference ratio but less than said seconddiscriminating reference ratio, discriminating as being no change in theurine sugar value.
 3. A urine sugar condition estimation method claimedin claim 2, wherein said discriminating method classification boundaryvalue is 50 mg/dL, and said positive discriminating reference differenceis 10 mg/dL, said negative discriminating reference difference is −10mg/dL, said first discriminating reference ratio is 0.8, and said seconddiscriminating reference ratio is 1.2.
 4. A urine sugar conditionestimation method claimed in claim 3, wherein said predetermined periodof time is selected from a range of five days from five weeks.
 5. Ablood sugar state estimation method, comprising the steps of: (1)measuring a urine sugar value A; (2) obtaining an averaged value X ofmeasured urine sugar values measured during a past predetermined periodof time, always including all measured urine sugar values measured atthe same timing in a one-day life as the timing when said latestmeasured urine sugar value A was measured; (3) discriminating whether ornot said measured urine sugar value A is less than a discriminatingmethod classification boundary value; (4) when the measured urine sugarvalue A is less than the discriminating method classification boundaryvalue, calculating a difference between said averaged value X and saidmeasured urine sugar value A; (5) when said difference {X−A} is not lessthan a positive discriminating reference difference, discriminating asbeing a blood sugar value decrease; (6) when the measured urine sugarvalue A is not less than the discriminating method classificationboundary value, calculating a ratio between said measured urine sugarvalue A and said averaged value X; and, (7) when said ratio {A/X} is notgreater than a first discriminating reference ratio, discriminating asbeing the blood sugar value decrease.
 6. A blood sugar state estimationmethod claimed in claim 5, further comprises the steps of: (8) when saiddifference {X−A} is not greater than a negative discriminating referencedifference, discriminating as being a blood sugar value increase; (9)when said difference {X−A} is greater than said negative discriminatingreference difference but less than said positive discriminatingreference difference, discriminating as being no change in the bloodsugar value; (10) when said ratio {A/X} is not less than a seconddiscriminating reference ratio, discriminating as being the blood sugarvalue increase; and (11) when said ratio {A/X} is greater than saidfirst discriminating reference ratio but less than said seconddiscriminating reference ratio, discriminating as being no change in theblood sugar value.
 7. A blood sugar condition estimation method claimedin claim 6, wherein said discriminating method classification boundaryvalue is 50 mg/dL, and said positive discriminating reference differenceis 10 mg/dL, said negative discriminating reference difference is −10mg/dL, said first discriminating reference ratio is 0.8, and said seconddiscriminating reference ratio is 1.2.
 8. A blood sugar conditionestimation method claimed in claim 7, wherein said predetermined periodof time is selected from a range of five days from five weeks.
 9. Ablood sugar state estimation method, comprising the steps of: (1)measuring a urine sugar value A; (2) discriminating whether or not thelatest HbA1c is less than a discriminating method classificationboundary value; (3) when said latest HbA1c is less than saiddiscriminating method classification boundary value, if said latestmeasured urine sugar value A was measured after a meal, obtaining anaveraged value X of all post-meal measured urine sugar values measuredduring a past predetermined short period of time including said latestmeasured urine sugar value A and an averaged value Y of all post-mealmeasured urine sugar values measured during a past predetermined longperiod of time; (4) comparing said averaged value X of the measuredurine sugar values measured during said past predetermined short periodof time with said averaged value Y of the measured urine sugar valuesmeasured during said past predetermined long period of time, anddiscriminating that a significant improvement is found if the ratio{X/Y} is not greater than a first reference value; (5) when said latestHbA1c is not less than said discriminating method classificationboundary value, obtaining an averaged value X of all measured urinesugar values measured during said past predetermined short period oftime including the latest measured urine sugar value A and an averagedvalue Y of all measured urine sugar values measured during said pastpredetermined long period of time; (6) comparing said averaged value Xof the measured urine sugar values measured during said pastpredetermined short period of time with said averaged value Y of themeasured urine sugar values measured during said past predetermined longperiod of time, and discriminating that a significant improvement isfound if the ratio {X/Y} is not greater than said first reference value.10. A blood sugar state estimation method claimed in claim 9, furthercomprises the steps of: (7) when said ratio {X/Y} is not less than asecond discriminating reference ratio, discriminating that a significantdeterioration is found; and (8) when said ratio {X/Y} is greater thansaid first discriminating reference ratio but less than said seconddiscriminating reference ratio, discriminating that neither thesignificant improvement nor the significant deterioration is found. 11.A blood sugar state estimation method claimed in claim 10, wherein saidpredetermined short period of time is not less than five days but notgreater than two weeks, and said predetermined long period of time is atleast two times said predetermined short period of time, and is not lessthan two weeks but not greater than two months.
 12. A blood sugar stateestimation method claimed in claim 10, wherein said predetermined shortperiod of time is one week and said predetermined long period of time isone month.
 13. A blood sugar state estimation method claimed in claim11, wherein said discriminating method classification boundary value ofHbA1c is 9%.
 14. A blood sugar condition estimation method comprisingthe steps of: (1) measuring a urine sugar value A; (2) obtaining anaveraged value X of measured urine sugar values, including the latestmeasured urine sugar value A, measured during a past predeterminedperiod of time at the same timing as the timing when said latestmeasured urine sugar value A was measured, and considering the averagedvalue X thus obtained as a target value; (3) comparing said targetvalue, namely, said averaged value X with said latest measured urinesugar value A, and discriminating that an improvement target is achievedwhen the difference {X−A} is not less than 0 (zero).